On Wed, Dec 12, 2018 at 09:18:11AM -0700, Jens Axboe wrote: > When boxes are run near (or to) OOM, we have a problem with the discard > page allocation in nvme. If we fail allocating the special page, we > return busy, and it'll get retried. But since ordering is honored for > dispatch requests, we can keep retrying this same IO and failing. Behind > that IO could be requests that want to free memory, but they never get > the chance. > > Allocate a fixed discard page per controller for a safe fallback, and use > that if the initial allocation fails. Do we need to allocate this per controller? One page for the whole driver may be sufficient to make forward progress, right?
